1. Field of the Invention
Embodiments of invention relate generally to optical devices and, more specifically but not exclusively relate to isolating optical beams.
2. Background Information
The need for fast and efficient optical-based technologies is increasing as Internet data traffic growth rate is overtaking voice traffic pushing the need for fiber optical communications. Transmission of multiple optical channels over the same fiber in the dense wavelength-division multiplexing (DWDM) system provides a simple way to use the unprecedented capacity (signal bandwidth) offered by fiber optics. Some examples of commonly used optical components in the system may include wavelength division multiplexed (WDM) transmitters and receivers, optical filter such as diffraction gratings, thin-film filters, fiber Bragg gratings, arrayed-waveguide gratings and optical isolators. Optical isolators are useful components for optical communication systems to protect both lasers and/or amplifiers from damage. In particular, optical isolators allow light to propagate in one direction, but do not allow light to propagate in the opposite direction. By isolating the lasers and/or amplifiers, the lasers and/or amplifiers can be protected from unwanted reflections, which helps improve stability. However, common optical isolators utilize magnetic-based principles, which are extremely difficult to integrate with waveguide based devices and/or can introduce undesired effects such as frequency shift in the output optical beam.